I'm basically the male version of this. Never more than a friend, never enough to be more. Girls I was interested in telling me I am attractive and "a great person" but for whatever reason, when I try to go for it, they eventually tell me "you're great, but..." and that's it. Laying out reasons to let me down gently but sometimes I'd prefer if they'd just give me the hard truth as to what it is about me that wasn't enough. I often times tend to like girls I've been friends with for some time, since I am more introverted and don't drink alcohol (for reasons) and don't like to party, so meeting "random" women is pretty much out of the question.
It fucking sucks and I can somewhat relate to you in this case, especially because I am now 25 and never had a relationship (I don't count the one at 16 that didn't go anywhere). I also feel like I'll never get a girl to "like" me in this way. I don't know why guys aren't asking you out - if everything you say is true, you should have them lining up. Or maybe they are just intimidated? Have you tried asking them out?